Search results
Results from the WOW.Com Content Network
The respiratory quotient (RQ or respiratory coefficient) is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body, when the body is in a steady state.
The closing capacity (CC) is the volume in the lungs at which its smallest airways, the respiratory bronchioles, collapse. It is defined mathematically as the sum of the closing volume and the residual volume.
Applying this analogy to different causes of hypoxemia should help reason out whether to expect an elevated or normal A-a gradient. As a general rule of thumb, any pathology of the alveolar-capillary unit will result in a high A-a gradient. The table below has the different disease states that cause hypoxemia. [2]
The alveolar air equation is not widely used in clinical medicine, probably because of the complicated appearance of its classic forms. The partial pressure of oxygen ( p O 2 ) in the pulmonary alveoli is required to calculate both the alveolar-arterial gradient of oxygen and the amount of right-to-left cardiac shunt , which are both clinically ...
Minute ventilation (or respiratory minute volume or minute volume) is the volume of gas inhaled (inhaled minute volume) or exhaled (exhaled minute volume) from a person's lungs per minute. It is an important parameter in respiratory medicine due to its relationship with blood carbon dioxide levels. It can be measured with devices such as a ...
Output of a spirometer. Vital capacity (VC) is the maximum amount of air a person can expel from the lungs after a maximum inhalation.It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume.
Lung volumes. Functional residual capacity (FRC) is the volume of air present in the lungs at the end of passive expiration. [1] At FRC, the opposing elastic recoil forces of the lungs and chest wall are in equilibrium and there is no exertion by the diaphragm or other respiratory muscles.
where RQ is the respiratory quotient (ratio of volume CO 2 produced to volume of O 2 consumed), is 21.13 kilojoules (5.05 kcal), the heat released per litre of oxygen by the oxidation of carbohydrate, and is 19.62 kilojoules (4.69 kcal), the value for fat. This gives the same result as the Weir formula at RQ = 1 (burning only carbohydrates ...